RFR JDK-8193479: test/hotspot/jtreg/compiler/codegen/Test6896617.java fails after JDK-8184947

[Xueming Shen]

Hi

Please help review the change for JDK-8193479

issue: https://bugs.openjdk.java.net/browse/JDK-8193479
webrev: http://cr.openjdk.java.net/~sherman/8193479/webrev

The internal interface ArrayEn/Decoder for ISO8859_1 has been removed
because it is no longer used by StringCoding class, but it appears it is
being used by hotspot Test6896617.java to verify the SSE instructions
on x86. The proposed change here is to simply restore the internal interface
ArrayEn/Decoder for ISO8859_1 to avoid blocking hotspot testing for now.

thanks,
Sherman